Emerging Floatable Photothermal Coupled Catalytic System for Solar‐to‐Hydrogen Conversion

Abstract Solar‐driven photocatalytic water splitting has emerged as a promising technology for clean H 2 production, owing to the advantages of simple equipment, mild reaction conditions, and zero‐carbon route. To improve solar‐to‐hydrogen conversion efficiency, photothermal system has been employed to broaden the optical absorption range. However, the conventional immersion photothermal system encounters the challenges of light‐blocking effect and thermal diffusion, which seriously diminishes its catalytic performance. Against this backdrop, a floatable photothermal coupled catalytic system has recently been proposed, which can absorb and utilize the full‐spectrum solar while limiting thermal diffusion, and the formed gas‐solid two‐phase reaction interface results in kinetically easier H 2 evolution as compared to the conventional gas‐liquid‐solid three‐phase interface. Moreover, the good scalability of this emerging system implies its promising industrialization prospects. This article provides a comprehensive summary on the advantages, recent crucial advancements and design principles of floatable photothermal system for solar‐to‐hydrogen conversion, in which examining the roles of the system components and exploring strategies to optimize their interactions for improved catalytic performance are highlighted. Furthermore, perspectives on the challenges and opportunities for developing advanced floatable photothermal systems and the next generation of multifunctional devices are provided.